Some conventional methods for coliform detection in water and foods rely on the use of highly-selective media. These procedures have a shortcoming in that injured cells might not grow and be detected on these inhibitory media. In one MPN method, injured coliforms are resuscitated in lactose broth (presumptive test) and then growth from positive tubes is transferred to a more selective medium (confirmed test). This two-step procedure permits recovery and multiplication of injured cells, but is laborious. We are simplifying this MPN procedure by combining the presumptive and confirmed tests into a single stage. A timed-release capsule is added, at the time of inoculation, to a 1% lactose-1% peptone presumptive broth. The capsule releases brilliant green and oxgall gradually over an 8-hr period; at this time the medium is fully selective. Thus, injured cells have an opportunity to recover before the medium becomes selective; the new procedure eliminates one set of tubes and the necessity to transfer positive-presumptive cultures. The combined presumptive-confirmed coliform test is being compared with several existing, routine methods for coliform analysis. Timed-release capsules will also be developed to combine the preenrichment-enrichment stages of analyses for salmonellae. It is expected that the combined bacteriological procedures will result in savings of time, materials, and labor. Thus, results of these bacteriological analyses would be available sooner, at less cost, and with less effort than is presently possible.